Lithium research relevant to KDR/SQM, page-8

2016 Chemistry paper on the hydrometallurgy of lithium and hydroflouric acid. It provides a handy overview of the processes of extraction, and looks specifically at acid leaching. www.mdpi.com/2075-163X/6/4/98/pdf

"Lithium is found in many minerals due to its high chemical reactivity. However, there are few minerals that have been used for the production of lithium compounds. The most important lithium mineral is spodumene, which generally is accompanied by quartz, feldspar, and mica [2,4]. Spodumene occurs naturally in A-phase, with a monoclinic structure of the pyroxene type. This structure is resistant to the attack of chemical agents, either gaseous or liquid. Spodumene transforms into its B-phase through calcination at 1373 K [1100C]; this phase is much more reactive and less resistant to ordinary chemical agents. The most common industrial processes for the extraction of lithium from spodumene are acid and alkaline digestion, and the ion exchange method. The products obtained through these methods are lithium carbonate, lithium hydroxide, and lithium chloride, respectively. Acid digestion is carried out with concentrated sulfuric acid at temperatures higher than 523 K, whereas alkaline digestion is carried out with CaCO3 [calcium] at 1313 K [1040C]. In the process of ion exchange, B-spodumene is heated with organic salts of sodium and potassium at 673 K [400C]. The sulfuric acid process has become the main method for the production of lithium carbonate from spodumene due to its high efficiency. However, these methods have intrinsic drawbacks, such as high levels of sulfate and heavy metal ions in the product, sophisticated process for recovering sodium sulfate, and high energy consumption [3,4]. Furthermore, in the sulfuric process, 0.95 tons of acid residue are generated for each ton of processed mineral; this indicates that only Li is recovered from B-spodumene, and Al and Si [aluminium and silicon] remain as waste."

The rest of the paper is concerned with a practical trial of acid leaching combined with kinetic agitation. It's interesting.
So: KDR is looking at hydroxide for batteries (?), this necessitates alkaline digestion of spod at 1040C.